Ansa group 4 metal bis (μ-substituted) aluminum complexes

ABSTRACT

Ansa bis(μ-substituted) Group 4 metal and aluminum compounds comprising a single Group 4 metal atom and two aluminum metal atoms corresponding to the formula: ##STR1## wherein: L&#39; is a π-bonded group, 
     M is a Group 4 metal, 
     J is nitrogen or phosphorus; 
     Z is a divalent bridging group causing the complex to have an ansa structure, 
     R&#39; is an inert monovalent ligand; 
     r is one or two; 
     X independently each occurrence is a Lewis basic ligand group able to form a μ-bridging ligand group, and optionally the two X groups may be joined together, and 
     A&#39; independently each occurrence is an aluminum containing Lewis acid compound that forms an adduct with the metal complex by means of the μ-bridging groups, and optionally two A&#39; groups may be joined together thereby forming a single difunctional Lewis acid containing compound, and a method of preparation comprising contacting a charge-neutral Group IV metal coordination complex having at least two Lewis basic groups with at least two molar equivalents of charge-neutral aluminum coordination complexes having Lewis acidic aluminum atoms such that at least two of the aluminum atoms of the aluminum coordination complexes bond to at least two of the Lewis basic groups of the Group IV coordination complex.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority benefit from provisional applications60/122,615, filed Mar. 3, 1999, 60/096,088, filed Aug. 11, 1998,60/104,229, filed Oct. 14, 1998, 60/096,800, filed Aug. 17, 1998 and60/100,490, filed Sep. 16, 1998.

BACKGROUND INFORMATION

The present invention relates to compounds that are useful as catalystsor catalyst components. More particularly, the present invention relatesto such compounds comprising two aluminum and one Group 4 metal atomthat are particularly adapted for use in the coordination polymerizationof unsaturated compounds. Such compounds are particularly advantageousfor use in a polymerization process wherein at least one polymerizablemonomer is combined under polymerization conditions with a catalyst orcatalyst composition to form a polymeric product.

It is previously known in the art to activate Ziegler-Nattapolymerization catalysts, particularly such catalysts comprising Group3-10 metal complexes containing delocalized π-bonded ligand groups, oneuses Lewis acids to form catalytically active derivatives of such Group3-10 metal complexes. Examples of suitable Lewis acids includetris(perfluorophenyl)borane and tris(perfluorobiphenyl)borane. Examplesof such processes are disclosed in U.S. Pat. No. 5,721,185 and J. Am.Chem. Soc., 118, 12451-12452 (1996), and elsewhere.

According to J. Chem. Soc. Chem. Commun., 1999, 115-116, certainspecifically substituted bis-Cp zirconocenedimethyl complexes may beconverted to a dicationic derivative at -60° C. using multipleequivalents of trispentafluorophenylborane. The resulting metallocenesrequired the presence of either pendant phosphine moieties or benzylgroups on the cyclopentadienyl ring system and two equivalents of themethyltris(pentafluorophenyl)borate anion for charge balance. Uponheating even to -40° C. the product decomposed to give the correspondingmonocationic complex and free tris(pentafluorophenyl)borane. Finally, inOrganometallics, 1998, 17, 5908-5912, the reaction of the strongly Lewisacidic compound, tris(pentafluorophenyl)aluminum, withbis(cyclopentadienyl)zirconium dimethyl was shown to form an unstable(μ-methyl) derivative via methide abstraction, which rapidly collapsedthrough a back exchange reaction at temperatures above 0° C. to formbis(cyclopentadienyl)methylpentafluoro-phenyl zirconium.

All of the foregoing attempts have failed to prepare abis(μ-substituted) derivative of a metal complex that is stable attemperatures greater than 0° C. for a time sufficiently long for suchcompound to be useful in catalytic applications, especially in thepolymerization of one or more ethylenically unsaturated monomers underaddition polymerization conditions. Moreover, there is no knownsuccessful preparation of bis(μ-substituted)aluminum derivatives of ametal complex under any circumstances.

SUMMARY OF THE INVENTION

According to the present invention there are now provided ansabis(μ-substituted) Group 4 metal and aluminum compounds corresponding tothe formula: ##STR2## wherein: L' is a π-bonded group,

M is a Group 4 metal,

J is nitrogen or phosphorus;

Z is a divalent bridging group causing the complex to have an ansastructure,

R' is an inert monovalent ligand;

r is one or two;

X independently each occurrence is a Lewis basic ligand group able toform a μ-bridging ligand group, and optionally the two X groups may bejoined together, and

A' independently each occurrence is an aluminum-containing Lewis acidcompound of up to 50 atoms other than hydrogen, that forms an adductwith the metal complex by means of the μ-bridging groups, and optionallytwo A' groups may be joined together thereby forming a singledifunctional Lewis acid containing compound.

In the compounds of the invention, some or all of the bonds between M,NR'_(r), X and A' may possess partial bond characteristics. In addition,when the nitrogen of NR'_(r) is not sterically hindered, particularlywhen R' is a primary alkyl group, an electronic interaction between thenitrogen and either one or both of the Lewis acid moieties, A', mayoccur.

The compounds of the invention may be formed by contacting acharge-neutral Group IV metal coordination complex having at least twoLewis basic groups or precursor(s) thereof (catalyst) with at least twomolar equivalents of a charge-neutral aluminum coordination complexhaving Lewis acidic aluminum atoms (activator) such that at least two ofthe aluminum atoms of the aluminum coordination complex bond to at leasttwo of the Lewis basic groups of the Group IV metal coordinationcomplex. Preferably the molar ratio of catalyst:activator is less than1:100, more preferably the ratio is from 1:2.1 to 1:10, and mostpreferably from 1:3 to 1:8.

The present invented compounds are stable at elevated temperatures of atleast 0° C., preferably at least 20° C. up to as high as 150° C. orhigher and are usefully employed in a process for polymerization ofethylenically unsaturated monomers under solution, slurry, highpressure, or gas phase polymerization conditions. Relatively highmolecular weight polymers may be readily obtained by use of the presentmetal complexes in the foregoing polymerization processes. Particularly,when employed in continuous solution or gas phase olefin polymerizationprocesses, the present invented complexes may provide polymers havingenhanced long chain branch incorporation and increased molecularweights.

Accordingly, the present invention additionally provides a process forthe polymerization of one or more ethylenically unsaturated,polymerizable monomers comprising contacting the same, optionally in thepresence of an inert aliphatic, alicyclic or aromatic hydrocarbon, underpolymerization conditions with the above metal complex, oralternatively, forming the above metal complex in situ in the presenceof or prior to addition to, a reaction mixture comprising one or moreethylenically unsaturated, polymerizable compounds.

DETAILED DESCRIPTION OF THE INVENTION

All references herein to elements belonging to a certain Group refer tothe Periodic Table of the Elements published and copyrighted by CRCPress, Inc., 1995. Also any reference to the Group or Groups shall be tothe Group or Groups as reflected in this Periodic Table of the Elementsusing the IUPAC system for numbering groups. Where any reference is madeherein to any publication, patent application or provisional patentapplication, the contents thereof are incorporated herein in itsentirety by reference. By the term "Lewis basic" and "Lewis acidic, inreference to ligand groups herein, is meant groups that are sufficientlynucleophilic or electrophilic respectively, such that the μ-bridgedcomplexes of the present invention are capable of formation. PreferredLewis basic ligand groups, X, are hydrocarbyl, silyl, N,N-dialkylamidoand alkanediylamido groups of up to 20 atoms not counting hydrogen, ortwo such X groups together are an alkanediyl or alkenediyl group whichtogether with M form a metallocycloalkane or metallocycloalkene.Preferred Lewis acids are aluminum compounds containing at least onehalohydrocarbyl ligand, preferably a fluoroaryl ligand. More preferredare tri(halohydrocarbyl)aluminum compounds having up to 50 atoms otherthan hydrogen, especially tri(fluoroaryl) aluminum compounds, mostpreferably tris(perfluoroaryl)aluminum compounds, and most highlypreferably tris(pentafluorophenyl)aluminum. The Lewis acid may be usedin pure form or in the form of an adduct with a Lewis base such as anether.

Suitable aluminum containing Lewis acids may be prepared by exchangebetween tris(pentafluorophenyl)boron and alkylaluminum- oralkyaluminumoxy-compounds such as alumoxanes ordiisobutyl(2,6-di-t-butyl-4-methylphenoxy)aluminum, as disclosed inBiagini et.al., U.S. Pat. No. 5,602,269, and provisional applications60/096,088 and 60/104,229. The aluminum containing Lewis acids may bepreviously prepared and used in a relatively pure state or generated insitu by any of the foregoing techniques in the presence of the metalcomplex. Tris(perfluoroaryl)aluminum and exchange products obtained bymixing tris(perfluoroaryl)borane complexes with methylalumoxane (MAO) ortrialkylaluminum-, especially, triisobutylaluminum- modifiedmethylalumoxane (MMAO) are highly preferred. This reaction product withan alumoxane comprises a tris(fluoraryl)aluminum component of high Lewisacidity and a form of alumoxane which is rendered more Lewis acidic bythe inherent removal of trimethylaluminum (TMA) via exchange to formtrimethylborane. Optimized reaction products of these reactionscorrespond to the empirical formula:

    (AlAr.sup.f.sub.3-w' Q.sup.1.sub.w').sub.w (AlAr.sup.f.sub.3-x' (OQ.sup.2).sub.x').sub.x (AlQ.sup.1.sub.3-y' (OQ.sup.2).sub.y').sub.y [(--AlQ.sup.2 --O--).sub.z' ].sub.z,

where;

Ar^(f) is a fluorinated aromatic hydrocarbyl moiety of from 6 to 30carbon atoms; preferably fluoroaryl, more preferably perfluoroaryl, andmost preferably pentafluorophenyl;

Q¹ is C₁₋₂₀ alkyl, preferably methyl;

Q² is C₁₋₂₀ hydrocarbyl, optionally substituted with one or more groupswhich independently each occurrence are hydrocarbyloxy,hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbylsilyl)amino,hydrocarbylamino, di(hydrocarbyl)amino, di(hydrocarbyl)phosphino, orhydrocarbylsulfido groups having from 1 to 20 atoms other than hydrogen,or, optionally, two or more Q² groups may be covalently linked with eachother to form one or more fused rings or ring systems;

w' is a number from 0 to 3;

w is a number from 0 to 1.0; preferably from 0.5 to 1.0, more preferablyfrom 0.8 to 1.0;

x' is a number from 0 to 3;

x is a number from 1.0 to 0; preferably from 0.5 to 0, more preferablyfrom 0.2 to 0;

y' is a number from 0 to 3;

y is a number from 1.0 to 0; preferably from 0.5 to 0, more preferablyfrom 0.2 to 0;

z' is a number from 0 to 30; and

z is a number from 0 to 20, preferably from 0 to 5, more preferably from0 to 0.5.

The moieties, (AlAr^(f) _(3-w') Q¹ _(w')), (AlAr^(f) _(3-x')(OQ²)_(x')), (AlQ¹ _(3-y') (OQ²)_(y')), and [(--AlQ² --O--)_(z') ], mayexist as discrete entities or as dynamic exchange products. That is, theforegoing formula is an idealized representation of the composition,which may actually exist in equilibrium with additional exchangeproducts.

Preferably, L' is a cyclic or non-cyclic, aromatic or non-aromatic,anionic or neutral ligand group containing delocalized π-electronscapable of forming a bond with the Group 4 metal. Exemplary of suchπ-bonded groups are conjugated or nonconjugated, cyclic or non-cyclicdiene and dienyl groups, allyl groups, boratabenzene groups, phosphole,and arene groups. Each atom in the delocalized π-bonded group mayindependently be substituted with a radical selected from the groupconsisting of hydrogen, halogen, hydrocarbyl, halohydrocarbyl,substituted heteroatom groups wherein the heteroatom is selected fromGroup 13-17 of the Periodic Table of the Elements, and the substituentsare hydrocarbyl, silyl, hydrocarbylene, or another Group 13-17heteroatom containing moiety, and optionally any of the foregoinghydrocarbyl, silyl, or hydrocarbylene substituents may be furthersubstituted with a Group 13-17 heteroatom group. In addition two or moresuch radicals may together form a fused ring system, including partiallyor fully hydrogenated fused ring systems. Included within the term"hydrocarbyl" are C₁₋₂₀ straight, branched and cyclic alkyl or alkenylradicals, C₆₋₂₀ aromatic radicals, C₇₋₂₀ alkyl-substituted aromaticradicals, and C₇₋₂₀ aryl-substituted alkyl radicals. Suitable heteroatomgroups include alkoxy, aryloxy, dialkylamino, alkanediylamino,dialkylphosphino, silyl, germyl, and siloxy groups containing from 1 to20 atoms not counting hydrogen. Examples include N,N-dimethylamino,pyrrolidinyl, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl,methyidi(t-butyl)silyl, triphenylgermyl, and tnmethylgermyl groups.

Examples of suitable anionic, delocalized π-bonded groups includecyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl,tetrahydrofluorenyl, octahydrofluorenyl, pentadienyl, cyclohexadienyl,dihydroanthracenyl, hexahydroanthracenyl, decahydroanthracenyl groups,indacenyl, cyclopenta(ophenanthrenyl, and boratabenzene groups, as wellas C₁₋₁₀ hydrocarbyl-substituted, C₁₋₁₀ amido- substituted, or C₁₋₁₀hydrocarbylsilyl-substituted derivatives thereof.

The boratabenzenes are anionic ligands that are boron-containinganalogues to benzene. They are previously known in the art having beendescribed by G. Herberich, et al., in Orcanometallics, 14,1, 471-480(1995). Preferred boratabenzenes correspond to the formula: ##STR3##wherein R'" in one occurrence is a covalent bond to Z, and in eachremaining occurrence R'" is independently, hydrogen or a hydrocarbyl,silyl, N,N-dihydrocarbylamino, hydrocarbadiylamino, or germyl group,said R'" having up to 20 atoms not counting hydrogen, and optionally oneor more R'" groups may be bonded together forming a multicyclic fusedring system.

Phospholes are anionic ligands that are phosphorus- containing analoguesto a cyclopentadienyl group. They are previously known in the art havingbeen described by WO 98/50392, and elsewhere. Preferred phospholeligands correspond to the formula: ##STR4## wherein R'" is as previouslydefined.

A preferred class of charge neutral Group 4 metal complexes usedaccording to the present invention and the resulting compounds of theinvention respectively correspond to the formulae: ##STR5## wherein: R'is hydrocarbyl or silyl of up to 20 atoms not counting hydrogen;

R" in each occurrence independently is selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, N,N-dialkylamino, andalkanediylamino, said R" having up to 20 atoms, not counting hydrogen,or adjacent R" groups are joined together thereby forming a fused ringsystem,

X independently each occurrence is hydrocarbyl, or two X groups togetherare an alkanediyl-, alkenediyl-, or neutral hydrocarbadiene- group, saidX having up to 20 atoms not counting hydrogen;

Z is SiR*₂, CR*₂, SiR*₂ SiR*₂, CR*₂ CR*₂, CR*═CR*, CR*₂ SiR*₂, BNR*₂, orGeR*₂, wherein R* independently each occurrence is C₁₋₄ alkyl or C₆₋₁₀aryl, or optionally two R* groups are joined together; and

M, and A' are as previously defined.

More preferred anionic delocalized π-bonded groups, L', arecyclopentadienyl, tetramethylcyclopentadienyl, indenyl,2,3-dimethylindenyl, fluorenyl, 2-methylindenyl,2-methyl-4-phenylindenyl, 3-dimethylaminoindenyl, 3-pyrrolidinoindenyl,3-piperidinoindenyl, tetrahydrofluorenyl, octahydrofluorenyl,1-indacenyl, 3,4-(cyclopenta(l)phenanthren-1-yl), and tetrahydroindenyl.

Most preferred charge neutral Group 4 metal complexes used according tothe present invention and the resulting compounds of the inventionrespectively correspond to the formulae: ##STR6## wherein: Cp* istetramethylcyclopentadienyl, 2-methyl-4-phenylinden-1 -yl,3-pyrrolidinoinden-1 -yl, 1-indacenyl, or3,4-(cyclopenta(l)phenanthren-1 -yl);

R' is C₁₋₁₀ alkyl or cycloalkyl; and

X is methyl or two X groups together are 2-butene-1,4-diyl,2,3-diphenyl-2-butene-1,4-diyl, 1,3-pentadiene or1,4-diphenyl-1,3-butadiene.

Examples of charge neutral metal complexes which may be used to preparethe compounds of the invention include:

(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium dimethyl,

(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium dimethyl,

(tert-butylamido)(hexamethyl-η⁵ -indenyl)dimethylsilanetitaniumdimethyl,

(dimethylamino)(tetramethyl-η⁵ -cyclopentadienyl)1,2-ethanediyltitanium(III) dimethyl,

(tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitaniumdimethyl,

(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium 2,3-dimethyl-2-butene-1,4-diyl,

(tert-butylamido)(tetramethy-η⁵ -cyclopentadienyl)dimethylsilanetitanium1,4-diphenyl-1,3-butadiene,

(tert-butylamido)(3-(N-pyrrolidino)inden-1-yl)dimethylsilanetitaniumdimethyl,

(tert-butylamido)(2-methyl-4-phenyl-inden-1-yl)dimethylsilanetitaniumdimethyl,

(tert-butylamido)(s-indacen-1-yl)dimethylsilanetitanium dimethyl,

(tert-butylamido)(3,4-(cyclopenta(l)phenanthren-1-yl))dimethylsilanetitaniumdimethyl,

(n-butylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumdimethyl,

(n-butylamido)(tetramethyl-η⁵ -cyclopentadienyl)-1,2-ethanediyltitaniumdimethyl,

(n-butylamido)(hexamethyl-η⁵ -indenyl)dimethylsilanetitanium dimethyl,

(di-ethylamino)(tetramethyl-η⁵ -cyclopentadienyf)1,2-ethanediyftitanium(III) dimethyl,

(n-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium dimethyl,

(n-butylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitanium2,3-dimethyl-2-butene-1,4-diyl,

(n-butylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitanium1,4-diphenyl-1,3-butadiene,

(n-butylamido)(3-(N-pyrrolidino)inden-1-yl)dimethylsilanetitaniumdimethyl,

(n-butylamido)(2-methyl-4-phenyl-inden-1-yl)dimethylsilanetitaniumdimethyl,

(n-butylamido)(s-indacen-1-yl)dimethylsilanetitanium dimethyl,

(n-butylamido)(3,4-(cyclopenta(l)phenanthren-1-yl))dimethylsilanetitaniumdimethyl,

(cyclohexylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium dimethyl,

(cyclohexylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium dimethyl,

(cyclohexylamido)(hexamethyl-η⁵ -indenyl)dimethylsilanetitaniumdimethyl,

(dimethylamino)(tetramethyl-η⁵ -cyclopentadienyl)dimethyl silanetitanium(III) dimethyl,

(cyclohexylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitaniumdimethyl,

cycdohexylami do)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium 2,3-dimethyl-2-butene-1,4-diyl,

cyclohexylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitanium2,3-diphenyl-1,3-butadiene,

(cyclohexylamido)(3-(N-pyrrolidino)inden-1-yl)dimethylsilanetitaniumdimethyl,

(cyclohexylamido)(2-methyl-4-phenyl-inden-1-yl)dimethylsilanetitaniumdimethyl,

(cyclohexylamido)(s-indacen-1-yl)dimethylsilanetitanium dimethyl,

(cycloheylamido)(3,4-(cyclopenta(l)phenanthren-1-yl))dimethylsilanetitaniumdimethyl.

Examples of bis(μ-substituted) Group 4 metal and aluminum metallocenecompounds of the invention include the following:

(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium μ-(dimethyl) bis(tris(pentafluorophenyl)aluminum),

(tert-butylamido)(hexamethyl-η⁵ -indenyl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(dimethylamino)(tetramethyl-η⁵ -cyclopentadienyl)1,2-ethanediyltitanium(III) μ-(dimethyl) bis(tris(pentafluorophenyl)aluminum),

(tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(tert-butylamido)(tetramethyl-η⁵ -cyclopentadienyl)μ-(2,3-dimethyl-2-butene-1,4-)bis(tris(pentafluorophenyl)aluminum),

(tert-butylamido)(3-(N-pyrrolidino)inden-1-yl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(tert-butylamido)(2-methyl-4-phenyl-inden-1-yl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(tert-butylamido)(s-indacen-1-yl)dimethylsilanetitanium μ-(dimethyl) bis(tris(pentafluorophenyl)aluminum),

(tert-butylamido)(3,4-(cyclopenta(ophenanthren-1-yl))dimethylsilanetitaniumμ-(dimethyl) bis(tris(pentafluorophenyl)aluminum),

(n-butylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(n-butylamido)(tetramethyl-η⁵ -cyclopentadienyl)-1,2-ethanediyltitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(n-butylamido)(hexamethyl-η⁵ -indenyl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(di-ethylamino)(tetramethyl-η⁵ -cyclopentadienyl)1,2-ethanediyltitanium(III) μ-(dimethyl) bis(tris(pentafluorophenyl)aluminum),

(n-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(n-butylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumμ-(2,3-dimethyl-2-butene-1,4-)bis(tris(pentafluorophenyl)aluminum),

(n-butylamido)(3-(N-pyrrolidino)inden-1-yl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(n-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(n-butylamido)(s-indacen-1-yl)dimethylsilanetitanium μ-(dimethyl) bis(tris(pentafluorophenyl)aluminum),

(n-butylamido)(3,4-(cyclopenta(ophenanthren-1-yl))dimethylsilanetitaniumμ-(dimethyl) bis(tris(pentafluorophenyl)aluminum),

(cyclohexylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium μ-(dimethyl)bis(tris(pentafluorophenyl)aluminum),

(cyclohexylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium μ-(dimethyl)bis(tris(pentafluorophenyl)aiuminum),

(cyclohexylamido)(hexamethyl-η⁵ -indenyI)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(dimethylamino)(tetramethyl-η⁵ -cyclopentadienyl)dimethyl silanetitanium(III) μ-(dimethyl) bis(tris(pentafluorophenyl)aluminum),

(cyclohexylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

cyclohexylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumμ-(2,3-dimethyl-2-butene-1,4-)bis(tris(pentafluorophenyl)aluminum),

(cyclohexylamido)(3-(N-pyrrolidino)inden-1-yl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(cyclohexylamido)(2-methyl-4-phenyl-inden-1-yl)dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum),

(cyclohexylamido)(s-indacen-1-yl)dimethylsilanetitanium μ-(dimethyl) bis(tris(pentafluorophenyl)aluminum), and

(cyclohexylamido)(3,4-(cyclopenta(Iphenanthren-1-yl))dimethylsilanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum).

The complexes of the invention are prepared in one embodiment byreacting an aluminum containing Lewis acid compound with a chargeneutral Group 4 metal complex containing a delocalized ligand group andan amido group, wherein the delocalized ligand group and amido group arecovalently bonded to one another by means of a bridging group, the molarratio of Lewis acid compound to Group 4 metal complex being at least2:1, preferably from 2:1 to 5:1, most preferably from 2:1 to 2.5:1. Theforegoing process may be illustrated by the following reaction scheme:##STR7## wherein: L', M, Z, R', X, r, and A' are as previously defined.

Preferably,

M is titanium;

R' is a hydrocarbyl or silyl group of up to 20 atoms not countinghydrogen;

X independently each occurrence is a monovalent hydrocarbyl or silylgroup, a trihydrocarbylsilyl-, trihydrocarbylgermyl- or halo-substituted derivative thereof, a N,N-dihydrocarbylamido group or ahydrocarbadiylamido group, said X containing up to 20 atoms not countinghydrogen, and optionally two X groups may be bound together;

r is one or two (if r is two the bond between N and M is acoordinate/covalent bond), preferably r is one; and

A' corresponds to the empirical formula:

(AlAr^(f) _(3-w') Q¹ _(w'))_(w) (AlAr^(f) _(3-x') (OQ²)_(x'))_(x) (AlQ¹_(3-y') (OQ²)_(y'))_(y) [(--AlQ² --O--)_(z') ]_(z), where;

Ar^(f) is a fluorinated aromatic hydrocarbyl moiety of from 6 to 30carbon atoms, preferably a perfluoroaryl group, and most preferablypentafluorophenyl;

Q¹ is C₁₋₂₀ alkyl, preferably methyl;

Q² is C₁₋₂₀ hydrocarbyl, optionally substituted with one or more groupswhich independently each occurrence are hydrocarbyloxy,hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbylsilyl)amino,hydrocarbylamino, di(hydrocarbyl)amino, di(hydrocarbyl)phosphino, orhydrocarbylsulfido groups having from 1 to 20 atoms other than hydrogen,or, optionally, two or more Q² groups may be covalently linked with eachother to form one or more fused rings or ring systems;

w' is a number from 0 to 3;

w is a number from 0 to 1.0; preferably from 0.5 to 1.0, more preferablyfrom 0.8 to 1.0;

x' is a number from 0 to 3;

x is a number from 1.0 to 0; preferably from 0.5 to 0, more preferablyfrom 0.2 to 0;

y' is a number from 0 to 3;

y is a number from 1.0 to 0; preferably from 0.5 to 0, more preferablyfrom 0.2 to 0;

z' is a number from 0 to 20; and

z is a number from 0 to 20, preferably from 0 to 5, more preferably from0 to 0.5.

Most preferably, A' is [(AlAr^(f) ₃) (AlAr^(f) ₂ Q¹)_(w") (--AlQ²--O--)_(z'))_(z) ], where,

w" is a number from 0 to 0.5, preferably from 0 to 0.1, more preferablyfrom 0 to 0.01; and

Ar^(f), Q¹, Q², z' and z are as previously defined.

Most preferably A' is AlAr^(f) ₃, wherein Ar^(f) is perfluorophenyl.

The process is conducted at temperatures from -80 to 220° C., preferablyfrom 25 to 50° C., and preferably in a hydrocarbon diluent or solvent,especially C₄₋₁₂ aliphatic, cycloaliphatic or aromatic hydrocarbons or amixture thereof. Certain of the foregoing metal complexes, particularlythose wherein R' is not particularly bulky, can share electrons betweenthe nitrogen atom and any resulting Abridging structure. Thus, theinitially formed compound (I) may convert over time to severaladditional complexes.

The term "stable" as used herein refers to metal complexes havingsufficient lifetimes to provide useful quantities of polymer under useconditions. The conversion products are not necessarily lacking inutility, and in fact, may be active catalyst species or necessaryintermediates thereto. One measure of the stability of the presentcomplexes is the determination of the compound's half-life under givenenvironmental conditions. The time in which one half of a given productis converted to a different compound or compounds can often be measured.Preferred stable compounds are further quantified as those compoundshaving a half-life of at least 1 second at a temperature greater than 0°C. For example, at approximately 25° C., conversion of the bis(μ-methyl)complex(t-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumμ-(dimethyl) bis (tris(pentafluorophenyl)aluminum) to the rearrangementproduct(t-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumpentafluorophenyl μ-methyl tris(pentafluorophenyl)aluminum, requiresseveral hours to reach conversions greater than 50 percent.

Since two M-X bonds are potentially available for activation in thecomplexes, it is believed, without wishing to be bound by such belief,that under actual polymerization conditions, two polymer chains maypropagate simultaneously or approximately simultaneously duringpolymerizations using the foregoing complexes, thereby providing greaterpotential for β-hydride elimination and α-olefin macromerreincorporation into the growing polymer chains under actual useconditions. Alternatively, the two μ-bridging moieties may interact,particularly where the Lewis acid groups are relatively labile, toproduce a single, highly active polymerization site.

Suitable addition polymerizable monomers for use with the foregoingnovel catalyst compositions include ethylenically unsaturated monomers,acetylenic compounds, conjugated or non-conjugated dienes, and polyenes.Preferred monomers include olefins, for example alpha-olefins havingfrom 2 to 20,000, preferably from 2 to 20, more preferably from 2 to 8carbon atoms and combinations of two or more of such alpha-olefins.Particularly suitable alpha-olefins include, for example, ethylene,propylene, 1-butene, isobutylene, 1-pentene, 4-methylpentene-1,1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene,1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, or combinationsthereof, as well as long chain vinyl terminated oligomeric or polymericreaction products formed during the polymerization, and C₁₀₋₃₀ α-olefinsspecifically added to the reaction mixture in order to producerelatively long chain branches in the resulting polymers. Preferably,the alpha-olefins are ethylene, propylene, 1-butene, 1-pentene,4-methyl-pentene-1, 1-hexene, 1-octene, and combinations of ethyleneand/or propene with one or more other alpha-olefins. Other preferredmonomers include styrene, halo- or alkyl substituted styrenes,vinylbenzocyclobutene, 1,4-hexadiene, dicyclopentadiene, ethylidenenorbornene, and 1,7-octadiene. Mixtures of the above-mentioned monomersmay also be employed.

In a further embodiment, the invention comprises a process for thepolymerization of α-olefins comprising contacting one or more α-olefinswith a catalyst composition comprising:

1) a group 4 metal complex corresponding to the formula: ##STR8##wherein, Z, L', M, X, R', and r are as previously defined with respectto formula I; and

2) tris(perfluorophenyl)aluminum,

wherein the equivalent ratio of metal complex: tris(perfluorophenyl)aluminum is from 1:2 to 1:5. The polymerization efficiency of theprocess is desirably at least twice, more preferably at least threetimes the efficiency of a comparable polymerization wherein theequivalent ratio of group 4 metal complex: tris(perfluorophenyl)aluminumis 1:1.

In general, the polymerization may be accomplished under conditions wellknown in the prior art for Ziegler-Natta or Kaminsky-Sinn typepolymerization reactions. Suspension, solution, slurry, gas phase orhigh pressure, whether employed in batch or continuous form or otherprocess conditions, may be employed if desired. Examples of such wellknown polymerization processes are depicted in WO 88/02009, U.S. Pat.Nos. 5,084,534, 5,405,922, 4,588,790, 5,032,652, 4,543,399, 4,564,647,4,522,987, and elsewhere. Preferred polymerization temperatures are from0-250° C. Preferred polymerization pressures are from atmospheric to3000 atmospheres.

Preferred processing conditions include solution polymerization, morepreferably continuous solution polymerization processes, conducted inthe presence of an aliphatic or alicyclic liquid diluent. By the term"continuous polymerization" is meant that at least the products of thepolymerization are continuously removed from the reaction mixture.Preferably one or more reactants are also continuously added to thepolymerization mixture during the polymerization. Examples of suitablealiphatic or alicyclic liquid diluents include straight andbranched-chain C₄₋₁₂ hydrocarbons and mixtures thereof; alicyclichydrocarbons such as cyclohexane, cycloheptane, methylcyclohexane,methylcycloheptane, and mixtures thereof; and perfluorinatedhydrocarbons such as perfluorinated C₄₋₁₀ alkanes, and the like.Suitable diluents also include aromatic hydrocarbons (particularly foruse with aromatic α-olefins such as styrene or ring alkyl-substitutedstyrenes) including toluene, ethylbenzene or xylene, as well as liquidolefins (which may act as monomers or comonomers) including ethylene,propylene, 1-butene, isobutylene, butadiene, 1-pentene, cyclopentene,1-hexene, cyclohexene, 3-methyl-1-pentene, 4-methyl-1-pentene,1,4-hexadiene, 1-octene, 1-decene, styrene, divinylbenzene,allylbenzene, vinyltoluene (including all isomers alone or inadmixture), and the like. Mixtures of the foregoing are also suitable.The foregoing diluents may also be advantageously employed during thesynthesis of the metal complexes and catalyst activators of the presentinvention.

In most polymerization reactions the molar ratio ofcatalyst:polymerizable compounds employed is from 10⁻¹² :1 to 10⁻¹ :1,more preferably from 10⁻¹² :1 to 10⁻⁵ :1.

The catalyst composition of the invention may also be utilized incombination with at least one additional homogeneous or heterogeneouspolymerization catalyst in separate reactors connected in series or inparallel to prepare polymer blends having desirable properties. Anexample of such a process is disclosed in WO 94/00500, equivalent toU.S. Ser. No. 07/904,770. A more specific process is disclosed incopending application U.S. Ser. No. 08/10958, filed Jan. 29, 1993. Theteachings of the foregoing publications and pending applications arehereby incorporated by reference.

Molecular weight control agents can be used in combination with thepresent cocatalysts. Examples of such molecular weight control agentsinclude hydrogen, trialkyl aluminum compounds or other known chaintransfer agents. A particular benefit of the use of the presentcocatalysts is the ability (depending on reaction conditions) to producenarrow molecular weight distribution α-olefin homopolymers andcopolymers in greatly improved catalyst efficiencies. Preferred polymershave Mw/Mn of less than 2.5, more preferably less than 2.3. Such narrowmolecular weight distribution polymer products are highly desirable dueto improved tensile strength properties.

The catalyst composition of the present invention can also be employedto advantage in the gas phase polymerization and copolymerization ofolefins, preferably by supporting the catalyst composition by anysuitable technique. Gas phase processes for the polymerization ofolefins, especially the homopolymerization and copolymerization ofethylene and propylene, and the copolymerization of ethylene with higheralpha olefins such as, for example, 1-butene, 1-hexene,4-methyl-1-pentene are well known in the art. Such processes are usedcommercially on a large scale for the manufacture of high densitypolyethylene (HDPE), medium density polyethylene (MDPE), linear lowdensity polyethylene (LLDPE) and polypropylene.

The gas phase process employed can be, for example, of the type whichemploys a mechanically stirred bed or a gas fluidized bed as thepolymerization reaction zone. Preferred is the process wherein thepolymerization reaction is carried out in a vertical cylindricalpolymerization reactor containing a fluidized bed of polymer particlessupported above a perforated plate, the fluidization grid, by a flow offluidization gas.

The gas employed to fluidize the bed comprises the monomer or monomersto be polymerized, and also serves as a heat exchange medium to removethe heat of reaction from the bed. The hot gases emerge from the top ofthe reactor, normally via a tranquilization zone, also known as avelocity reduction zone, having a wider diameter than the fluidized bedand wherein fine particles entrained in the gas stream have anopportunity to gravitate back into the bed. It can also be advantageousto use a cyclone to remove ultra-fine particles from the hot gas stream.The gas is then normally recycled to the bed by means of a blower orcompressor and one or more heat exchangers to strip the gas of the heatof polymerization.

A preferred method of cooling of the bed, in addition to the coolingprovided by the cooled recycle gas, is to feed a volatile liquid to thebed to provide an evaporative cooling effect. The volatile liquidemployed in this case can be, for example, a volatile inert liquid, forexample, a saturated hydrocarbon having about 3 to about 8, preferably 4to 6, carbon atoms. In the case that the monomer or comonomer itself isa volatile liquid or can be condensed to provide such a liquid, this canbe suitably be fed to the bed to provide an evaporative cooling effect.Examples of olefin monomers which can be employed in this manner areolefins containing from about 3 to about eight, preferably from 3 to sixcarbon atoms. The volatile liquid evaporates in the hot fluidized bed toform gas which mixes with the fluidizing gas. If the volatile liquid isa monomer or comonomer, it may undergo some polymerization in the bed.The evaporated liquid then emerges from the reactor as part of the hotrecycle gas, and enters the compression/heat exchange part of therecycle loop. The recycle gas is cooled in the heat exchanger and, ifthe temperature to which the gas is cooled is below the dew point,liquid will precipitate from the gas. This liquid is desirably recycledcontinuously to the fluidized bed. It is possible to recycle theprecipitated liquid to the bed as liquid droplets carried in the recyclegas stream, as described, for example, in EP-A-89691, U.S. Pat. No.4,543,399, WO 94/25495 and U.S. Pat. No. 5,352,749, which are herebyincorporated by reference. A particularly preferred method of recyclingthe liquid to the bed is to separate the liquid from the recycle gasstream and to reinject this liquid directly into the bed, preferablyusing a method which generates fine droplets of the liquid within thebed. This type of process is described in WO 94/28032, the teachings ofwhich are also hereby incorporated by reference.

The polymerization reaction occurring in the gas fluidized bed iscatalyzed by the continuous or semi-continuous addition of catalyst.Such catalyst can be supported on an inorganic or organic supportmaterial if desired. The catalyst can also be subjected to aprepolymerization step, for example, by polymerizing a small quantity ofolefin monomer in a liquid inert diluent, to provide a catalystcomposite comprising catalyst particles embedded in olefin polymerparticles.

The polymer is produced directly in the fluidized bed by catalyzed(co)polymerization of the monomer(s) on the fluidized particles ofcatalyst, supported catalyst or prepolymer within the bed. Start-up ofthe polymerization reaction is achieved using a bed of preformed polymerparticles, which, preferably, is similar to the target polyolefin, andconditioning the bed by drying with a dry inert gas such as nitrogenprior to introducing the catalyst, the monomer(s) and any other gaseswhich it is desired to have in the recycle gas stream, such as a diluentgas, hydrogen chain transfer agent, or an inert condensable gas whenoperating in gas phase condensing mode. The produced polymer isdischarged continuously or discontinuously from the fluidized bed asdesired, optionally exposed to a catalyst kill and optionallypelletized.

EXAMPLES

It is understood that the present invention is operable in the absenceof any component which has not been specifically disclosed. Thefollowing examples are provided in order to further illustrate theinvention and are not to be construed as limiting. Unless stated to thecontrary, all parts and percentages are expressed on a weight basis. Theterm "overnight", if used, refers to a time of approximately 16-18hours, "room temperature", if used, refers to a temperature of about20-25° C., and "mixed alkanes" refers to a mixture of hydrogenatedpropylene oligomers, mostly C₆ -C₁₂ isoalkanes, available commerciallyunder the trademark Isopar E™ from Exxon Chemicals Inc.

Tris(perfluorophenyl)aluminum (C₆ F₅)₃ Al (FAAL, as a toluene adduct orsolvate free FAAL) was prepared by exchange reaction betweentris(perfluorophenyl) borane and trimethylaluminum, substantially asreported by Biagini et al., U.S. Pat. No. 5,602,269. All solvents werepurified using the technique disclosed by Pangborn et al,Organometallics, 15, 1518-1520, (1996). All compounds, solutions, andreactions were handled under an inert atmosphere (dry box). All chemicalshifts for ¹⁹ F NMR spectra were relative to a fixed external standard(CFCl₃) in benzene-d₆ or toluene-d₈, both of which were dried over Na/Kalloy and filtered or distilled prior to use. ¹ H and ¹³ C NMR shiftswere referenced to internal solvent resonances and are reported relativeto TMS.

Example 1

Reaction of(t-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumdimethyl with two equivalents of tris(pentafluorophenyl)aluminum##STR9##

NMR reactions were carried out in J-Young NMR tubes or NMR tubes withgood seals, and the samples were loaded into the NMR tubes in a glovebox after mixing the above two reagents((t-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumdimethyl and FAAL) in 0.7 mL of benzene-d₆ in a 1:2 ratio (0.02 mmolscale). The mixture was allowed to react at room temperature for 20 minbefore the NMR spectra were recorded. An orange solution was observedand the NMR data are consistent with the structure shown in the aboveequation. This species has a half-life of about 2.5 h at roomtemperature.

Spectroscopic data for Me₂ Si(η⁵ -Me₄ C₅)(t-BuN)Ti[(μ-Me)Al(C₆ F₅)₃ ]₂are as folllows. ¹ H NMR (C6D₆, 23° C.): δ 1.61 (s, 6 H, C₅ Me₄), 1.49(s, 6 H, C₅ Me₄), 1.07 (s, 9 H, N-t-Bu), 0.48 (s br, 6 H, Al-μ-Me), 0.22(s, 6 H, SiMe₂). ¹⁹ F NMR (C₆ D₆, 23° C.): δ -122.92 (d, ³ J_(F-F) =15.3Hz, 12 F, o-F), -152.23 (s br, 6 F, p-F), -161.15 (t, ³ J_(F-F) =18.3Hz, 12 F, m-F). ¹³ C NMR (C₆ D₆, 23° C.): δ 33.23 (NCMe₃), 33.02 (s br,Al-μ-Me), 15.09 (C₅ Me₄), 11.71 (C₅ Me₄), 4.72 (SiMe₂).

Example 2

Reaction of(t-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumdimethyl with two equivalents of tris(pentafluorophenyl)aluminum, 24hour study ##STR10##

NMR reactions were carried out in J-Young NMR tubes or NMR tubes withgood seals, and the samples were loaded into the NMR tubes in a glovebox after mixing the above two reagents((t-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniu mdimethyl and FAAL) in 0.7 mL of benzene-d₆ in a 1:2 ratio (0.02 mmolscale). The mixture was allowed to react at room temperature and thereaction was monitored by NMR measurements. The initially formedbis(μ-methyl) species Me₂ Si(η⁵ -Me₄ C₅)(t-BuN)Ti[(μ-Me)Al(C₆ F₅)₃ ]₂was slowly converted over 24 hours in quantitative yield to two speciesMe₂ Si(η⁵ -Me₄ C₅)(t-BuN)Ti(C₆ F₅)(μ-Me)Al(C₆ F₅)₃ and [(C₆ F₅)₂ AlMe]₂shown in the above equation.

Spectroscopic data for Me₂ Si(η⁵ -Me₄ C₅)(t-BuN)Ti(C₆ F₅) (μ-Me)Al(C₆F₅)₃ are as follows. ¹ H NMR (C₆ D₆, 23° C.): δ 1.73 (s, 3 H, C₅ Me₄),1.71 (s, 3 H, C₅ Me₄), 1.37 (s, 3 H, C₅ Me₄), 1.24 (s, 3 H, C₅ Me₄),1.00 (s, 9 H, N-t-Bu), 0.49 (s br, 3 H, Al-μ-Me), 0.31 (s, 3 H, SiMe₂),0.29 (s, 3 H, SiMe₂). ¹⁹ F NMR (C₆ D₆, 23° C.): δ -108.36 (d, ³ J_(F-F)=22.5 Hz, 1 F, C₆ F₅), -122.37 (d, ³ J_(F-F) =20.5 Hz, 6 F, o-F),-123.94 (d, ³ J_(F-F) =21.5 Hz, 1 F, C₆ F₅), -148.67 (t, ³ J_(F-F) =18.3Hz, 1 F, C₆ F₅), -153.50 (t, ³ J_(F-F) =21.4 Hz, 3 F, p-F), -159.12 (t,³ J_(F-F) =21.5 Hz, 1 F, C₆ F₅), -160.26 (t, ³ J_(F-F) =21.5 Hz, 1 F, C₆F₅), -161 (t, ³ J_(F-F) =19.5 Hz, 6 F, m-F). ¹³ C NMR (C₆ D₆, 23° C.): δ6 67.59 (s, NCMe₃), 32.98 (q, J_(C-H) =127.1 Hz, NCMe₃), 25.96 (br,Al-μ-Me), 15.77 (q, C₅ Me₄), 15.43 (q, C₅ Me₄), 12.18 (q, C₅ Me₄), 11.81(q, C₅ Me₄), 4.85 (q, SiMe₂), 4.23 (q, SiMe₂). Spectroscopic data for[(C₆ F₅)₂ AlMe]₂ are as follows. ¹ H NMR (C₆ D₆, 23° C.): δ -0.15 (s br,3 H, Al-Me). ¹⁹ F NMR (C₆ D₆, 23° C.): δ -123.06 (s br, 4 F, o-F),-151.34 (s br, 2 F, p-F), -160.97 (s br, 4 F, m-F). ¹³ C NMR (C₆ D₆, 23°C.): δ-6.38 (Al-Me).

Example 3

Reaction of(n-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumdimethyl with two equivalents of tris(pentafluorophenyl)aluminum##STR11## A. Preparation ofN-n-butylamino(dimethyl)tetramethylcyclopentadienylsilane

To a solution of 7.06 g (32.9 mmol) ofchloro(dimethyl)tetramethylcyclopentadienylsilane in about 100 mL ofhexane was slowly added about 8.0 mL (5.9 g, 8.1 mmol) of n-butylamine.Voluminous precipitate formed immediately. The reaction mixture wasstirred overnight, filtered, the solids were extracted with hexane, andthe volatiles were removed from the combined filtrates to give a paleyellow liquid. Yield: 8.09 g, 97.8 percent.

¹ H NMR (C₆ D₆): d 2.83 (s, 1H, NH), 2.63 (q, J=6.7 Hz, 2H, CH₂), 1.99(s, 6H, C₅ Me₄), 1.85 (s, 6H, C₅ Me₄), 1.25 (br m, 4H, CH₂ CH₂), 0.88(t, J=6.9 Hz, 3H, CH₃), 0.17 (s, 1H, SiCH), 0.01 (s, 6H, SiMe₂). ¹³ C(C₆ D₆): d 135.4, 132.8, 56.9, 42.1, 37.4, 20.5, 14.8, 14.4, 11.6, -2.1.

B. Preparation of dilithiumN-n-butylamido(dimethyl)tetramethylcyclopentadienylsilane

To a solution of 8.04 g (32.0 mmol) ofN-n-butylamino(dimethyl)tetramethylcyclopentadienylsilane in about 80 mLof hexane was added 42.0 mL (1.6 M, 67.2 mmol) of n-butyl lithium inhexane. The reaction mixture gradually became a thick, clear, colorless,viscous liquid in which the magnetic stir bar stirred very slowly. Tothis solution were added about 8 mL of diethyl ether, after which thestirring proceeded more easily. After the reaction mixture had beenallowed to stir over the weekend, some THF was added to the reactionmixture and stirring was continued for a few more hours. The volatileswere then removed under vacuum to give a dry, glassy solid. The yieldwas 10.03 g. NMR spectra did not reveal the presence of ether.

¹ H NMR (THF d-8): d 2.64 (br, 2H, CH₂), 2.00 (s, 6H, C₅ Me₄), 1.99 (s,6H, C₅ Me₄), 1.16 (s, 2H, CH₂), 1.15 (br, 2H, CH₂), 0.87 (t, J=5.7 Hz,3H, CH₃), -0.05 (s, 6H, SiMe₂). ¹³ C (THF d-8): d 115.4, 111.3, 50.6,42.6, 22.4, 15.2, 11.6, 8.1, 2.9.

C. Preparation of[N-n-butylamido(dimethyl)tetramethylcyclopentadienylsilane]titaniumdichloride

As dry powders, 5.952 g (22.60 mmol) of dilithiumN-n-butylamido(dimethyl)-tetramethylcyclopentadienylsilane and 8.375 g(22.60 mmol) of titanium (III) chloride tris(tetrahydrofuranate) weremixed thoroughly together in a jar. About 200 mL of THF were added tothis mixture to form instantly a very dark-colored blackish-brownsolution. After about 15 minutes stirring, 6.46 g (23.2 mmol) of lead(II) chloride were added. Within about 2 min, the color was yellowishdark brown. The reaction mixture was left to stir for several days. Thevolatiles were then removed under reduced pressure, the residue wasextracted with hexane, the mixture was filtered, and the filtrate wasconcentrated, then placed in a -35° freezer for several days. Theresulting yellow-green precipitate was filtered out, washed with coldhexane, re-extracted with hexane and filtered. The resulting yellowsolution was concentrated to a slurry which was then chilled in thefreezer for two days. The product was filtered, washed with hexane, anddried under reduced pressure to give 3.84 g of bright yellow powder. Thesupernatant was concentrated and re-chilled in the freezer to yield moreproduct. This process was repeated two more times to give a total yieldof 4.03 g (48.5 percent) of product.

¹ H NMR (C₆ D₆): d 4.23 (t, J=7.5 Hz, 2H, CH₂), 2.00 (s, 6H, C₅ Me₄),1.98(s, 6H, C₅ Me₄), 1.43 (m, from 1.37-1.47 ppm, 2H, CH₂), 1.22 (m,from 1.16-1.28 ppm, 2H, CH₂), 0.84 (t, J=7.3 Hz, 3H, CH₃), 0.35 (s, 6H,SiMe₂). ¹³ C (C₆ D₆): d 140.4, 135.7, 102.7, 55.7, 35.1, 21.0, 16.2,14.2, 13.0, 2.9.

D. Preparation of[N-n-butylamido(dimethyl)tetramethylcyclopentadienylsilane]titaniumdimethyl

To a solution of 2.284 g (6.20 mmol) of[N-n-butylamido(dimethyl)-tetramethylcyclopentadienylsilane]titaniumdichloride in about 80 mL of diethyl ether were added 8.26 mL of 1.5 M(12.4 mmol) methyl magnesium chloride in THF over a period of about 10minutes with the instant formation of bright yellow precipitate whichturned white over the course of the addition. The reaction mixture wasstirred overnight. The volatiles were removed under reduced pressure andthe residue was extracted with hexane and filtered. After concentratinguntil solid began to form, the solution was chilled overnight at -35° C.The pale yellow crystal product that resulted was isolated. The totalyield, after a second and third crop of crystalline product had beenisolated, was 0.964 g, 47.5 percent.

¹ H NMR (C₆ D₆): d 4.20 (t, J=7.3 Hz, 2H, CH₂), 1.98 (s, 6H, C₅ Me₄),1.88 )s, 6H, C₅ Me₄), 1.65 (m, from 1.60-1.70 ppm, 2H, CH₂), 1.40 (m,from 1.34-1.46 ppm, 2H, CH₂), 0.95 (t, J=7.3 Hz, 3H, CH₃), 0.48 (s, 6H,SiMe₂), 0.36 (s, 6H, TiMe₂). ¹³ C (C₆ D₆): d 134.1, 96.4, 51.1, 49.9,37.5, 21.0, 15.1, 14.3, 11.9, 3.3. (J_(CH) TiMe =118 Hz).

E. Preparation of[N-n-butylamido(dimethyl)tetramethylcyclopentadienylsilane]titaniumbis[(μ-methyl)aluminum tris(pentafluorophenyl)]

NMR reactions were carried out in J-Young NMR tubes or NMR tubes withgood seals, and the samples were loaded into the NMR tubes in a glovebox after mixing the above two reagents((n-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumdimethyl (prepared analogously to the teachings of U.S. Pat. No.5,703,187) and FAAL) in 0.7 mL of benzene-d₆ in a 1:2 ratio (0.03 mmolscale). The mixture was allowed to react at room temperature for 10 to15 min before the NMR spectra were recorded. A dark green solution wasobtained and the NMR data are consistent with the structure as shown inthe above equation.

Spectroscopic data for Me₂ Si(η⁵ -Me₄ C₅)[n-BuN-Al(C₆F₅)₃)-Me]Ti(μ-Me)Al(C₆ F₅)₃ are as follows. ¹ H NMR (C₆ D₆, 23° C.): δ4.51-4.43 (m, 1 H, N--CH₂ --), 4.06-3.96 (m, 1 H, N--CH₂ --), 1.73 (s, 3H, C₅ Me₄), 1.72 (s, 3 H, C₅ Me₄), 1.40 (s, 3 H, C₅ Me₄), 1.33 (s, 3 H,C₅ Me₄), 1.20-0.97 (m, 4 H, --CH₂ --CH₂ --), 0.70 (t, 3 H, --CH₃), 0.46(s br, 3 H, Al-μ-Me), 0.29 (s, 3 H, SiMe₂), 0.25 (s, 3 H, SiMe₂), -0.02,-0.26 (s br, 3 H, N--Al--μ--Me). ¹⁹ F NMR (C₆ D₆, 23° C.): δ-122.23 (sbr, 2 F, o-F), -122.84 (d, ³ J_(F-F) =20.5 Hz, 6 F, o-F), -123.03 (s br,4 F, o-F), -148.10 (t, ³ J_(F-F) =18.3 Hz, 1 F, p-F), -150.9 (s br, 1 F,p-F), -151.6 (s br, 1 F, p-F), -153.59 (t, ³ J_(F-F) =19.7 Hz, 3 F,p-F), -159.61 (s br, 2 F, m-F), -160.69 (s br, 2 F, m-F), -161.13 (s br,2 F, m-F), -161.74 (t, ³ J_(F-F) =19.5 Hz, 6 F, m-F). ¹³ C NMR (C₇ D₈,23° C.): δ 54.89 (N--CH₂ --), 35.38 (N--CH₂ --CH₂ --), 20.75 (N--CH₂--CH₂ --CH₂ --), 15.61 (C₅ Me₄), 15.29 (C₅ Me₄), 13.41 (--CH₃), 12.22(C₅ Me₄), 11.55 (C₅ Me₄), 2.62 (SiMe₂), 1.30 (SiMe₂).

Comparative 1

Reaction of(t-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumdimethyl with one equivalent of tris(pentafluorophenyl)aluminum##STR12##

NMR reactions were carried out in J-Young NMR tubes or NMR tubes withgood seals, and the samples were loaded into the NMR tubes in a glovebox after mixing the above two reagents (t-Bu-CGC and FAAL) in 0.7 mL ofbenzene-d₆ in a 1:1 ratio (0.02 mmol scale). The mixture was allowed toreact at room temperature for 20 min before the NMR spectra wererecorded. A yellow green solution was observed and the NMR data areconsistent with the structure shown in the above equation. This specieshas a half-life of about 5 days at room temperature.

Spectroscopic data for Me₂ Si(η⁵ -Me₄ C₅)(t-BuN)TiMe(μ-Me)Al(C₆ F₅)₃ areas follows. ¹ H NMR (C₆ D₆, 23° C.): δ 1.69 (s, 3 H, C₅ Me₄), 1.57 (s, 3H, C₅ Me₄), 1.55 (s, 3 H, C₅ Me₄), 1.43 (s, 3 H, C₅ Me₄), 1.11 (s, 9 H,N-t-Bu), 0.79 (s, 3 H, Ti-Me), 0.26 (s, 3 H, SiMe₂), 0.18 (s, 3 H,SiMe₂), 0.08 (s br, 3 H, Al-μ-Me). ¹⁹ F NMR (C₆ D₆, 23° C.) δ 122.70 (d,³ J_(FF) =20.5 Hz, 6 F, o-F), -153.85 (t, ³ J_(F-F) =19.7 Hz, 3 F, p-F),-161.76 (t, ³ J_(F-F) =19.5 Hz, 6 F, m-F). ¹³ C NMR (C₆ D₆, 23° C.): δ150.28 (d, J_(C-F) =230.8 Hz), 141.58 (d, J_(C-F) =251.3 Hz), 141.21,and 137.33 (d, J_(C-F) =261.1 Hz) for C₆ F₅ groups, 139.01, 138.44,129.28, 128.50, and 103.99 for C₅ Me₄, 66.55 (Ti-Me), 62.50 (NCMe₃),33.29 (NCMe₃), 19.63 (s br, Al-μ-Me), 15.85 (C₅ Me₄), 14.13 (C₅ Me₄),11.93 (C₅ Me₄), 11.44 (C₅ Me₄), 5.10 (SiMe₂), 4.60 (SiMe₂).

Comparative 2

Reaction of(n-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumdimethyl with one equivalent of tris(pentafluorophenyl)aluminum##STR13##

NMR reactions were carried out in J-Young NMR tubes or NMR tubes withgood seals, and the samples were loaded into the NMR tubes in a glovebox after mixing the above two reagents((n-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitaniumdimethyl and FAAL) in 0.7 mL of benzene-d₆ in a 1:1 ratio (0.03 mmolscale). The mixture was allowed to react at room temperature for 20 minbefore the NMR spectra were recorded. A yellow-green colored solutionwas obtained and the NMR data are consistent with the structure as shownin the above equation. Spectroscopic data for Me₂ Si(η⁵ -Me₄C₅)(n-BuN)TiMe(μ-Me)Al(C₆ F₅)₃ are as follows. ¹ H NMR (C₆ D₆, 23° C.):δ 4.30-4.20 (m, 1 H, N--CH₂ --), 3.91-3.82 (m, 1 H, N--CH₂ --), 1.71 (s,3 H, C₅ Me₄), 1.62 (s, 3 H, C₅ Me₄), 1.56 (s, 3 H, C₅ Me₄), 1.48 (s, 3H, C₅ Me₄), 1.29-1.11 (m, 4 H, --CH₂ --CH₂ --), 0.79 (t, 3 H, --CH₃),0.73 (s, 3 H, Ti--Me), 0.20 (s, 3 H, SiMe₂), 0.13 (s br, 3 H, Al-μ-Me),0.10 (s, 3 H, SiMe₂). ¹⁹ F NMR (C₆ D₆, 230° C.): δ -122.92 (d, ³ J_(F-F)=20.5 Hz, 6 F, o-F), -153.83 (t, ³ J_(F-F) =19.7 Hz, 3 F, p-F), -161.81(t, ³ J_(F-F) =19.5 Hz, 6 F, m-F). ³ C NMR (C₇ D₈, 23° C.): δ 64.98(Ti-Me), 54.36 (N--CH₂ --), 36.14 (N--CH₂ --CH₂ --), 20.75 (N--CH₂ --CH₂--CH₂ --), 15.69 (C₅ Me₄), 14.07 (C₅ Me₄), 13.64 (--CH₃), 11.87 (C₅Me₄), 11.23 (C₅ Me₄), 2.68 (SiMe₂), 1.46 (SiMe₂). The half-life of theabove species is about 48 hours at room temperature.

Polymerizations

All liquid and gas feeds were passed through columns of alumina and adecontaminant (Q-5™ catalyst available from Englehardt Chemicals Inc.)prior to introduction into the reactor. Catalyst components are handledin a glovebox containing an atmosphere of argon or nitrogen. A stirred2.0 liter reactor is charged with about 740 g of mixed alkanes solventand 118 g of 1-octene comonomer. Hydrogen is added as a molecular weightcontrol agent by differential pressure expansion from a 75 mL additiontank at 25 psi (2070 kPa). The reactor is heated to the polymerizationtemperature of 130° C. and saturated with ethylene at 500 psig (3.4MPa). Dimethylsilyl(tetramethylcyclopentadienyl)(t-butylamido)titaniumdimethyl and activator (FAAL in a molar ratio between 1:1 and 1:4 forthe invention) or trispentafluorophenylborane (FAB), as dilute solutionsin toluene, were mixed and transferred to a catalyst addition tank andinjected into the reactor. The polymerization conditions were maintainedfor 15 minutes with ethylene added on demand. The resulting solution wasremoved from the reactor, quenched with isopropyl alcohol, andstabilized by addition of 10 ml of a toluene solution containingapproximately 67 mg of a hindered phenol antioxidant (Irganox™ 1010 fromCiba Geigy Corporation) and 133 mg of a phosphorus stabilizer (Irgafos168 from Ciba Geigy Corporation).

Between polymerization runs, a wash cycle was conducted in which 850 gof mixed alkanes was added to the reactor and the reactor was heated to150° C. The reactor was then emptied of the heated solvent immediatelybefore beginning a new polymerization run.

Polymers were recovered by drying in a vacuum oven set at 140° C. forabout 20 hours. Density values are derived by determining the polymer'smass when in air and when immersed in methylethyl ketone. Micro meltindex values (MMI) are obtained using a Custom Scientific InstrumentInc. Model CS-127MF-015 apparatus at 190° C., and are unit less valuescalculated as follows: MMI=1/(0.00343 t-0.00251), where t=time inseconds as measured by the instrument. Results are contained in Table 1.

                                      TABLE 1                                     __________________________________________________________________________       Acti-                                                                             Catalyst/                                                                          ΔT                                                                         Yield                                                                            Efficiency                                                                            Density                                                                              Mw                                             Run vator activator.sup.1 (° C.) (g) (g polymer/μg Ti) g/ml                                           MMI (10.sup.3) Mw/Mn                      __________________________________________________________________________    1  FAAL                                                                              0.5/2                                                                              30.6                                                                             57.2                                                                             2.4     0.903                                                                             6.8                                                                              -- --                                          2 " 1/4 23.0 76.3 1.6 0.901 7.9 -- --                                         3 " 1/2 0.7 32.8 0.7 0.902 1.9 102 1.99                                       4* " 1/1 0.3 15.5 0.3 0.901 1.7 108 2.06                                      5* FAB 1/4 2.1 68.7 1.4 0.897 9.9 66.1 1.96                                   6* " 1/2 1.4 69.2 1.45 0.900 7.5 69.8 1.96                                    7* " 1/1 0.2 58.4 1.22 0.900 5.4 76.5 2.02                                  __________________________________________________________________________     *comparative, not examples of the invention. In run 4 insufficient FAAL       was used. In runs 5-7 the activator was FAB. Runs 4-7 did not form bridge     bisadducts.                                                                   .sup.1. μmoles/μmoles                                              

Example 4

In a glove box, FAAL (0.032 mmol, toluene adduct) anddi(isobutyl)(2,6-di-tert-butyl-4-methylphenoxy)aluminum (DIBAL-BOT)(0.008 mmol) were mixed in 0.7 mL of benzene-d₆ and the mixture wasloaded into a NMR tube. Two new species,isobutyl(pentafluorophenyl)(2,6-ditert-butyl-4-methylphenoxy)aluminum(i-Bu(C₆ F₅)Al(BHT)) and isobutylbis(pentafluorophenyl)aluminum(i-BuAl(C₆ F₆)₂), as well as a small amount ofbis(pentafluorophenyl)(2,6-ditert-butyl-4-methylphenoxy)aluminum ((C₆F₅)₂ Al(BHT)) were found to form from the exchange reaction. Nodi(isobutyl)(2,6-di-tert-butyl-4-methylphenoxy)aluminum reagentremained. Residual FAAL reagent was also present.

iBu(C₆ F₅)Al(BHT) ¹ H NMR (C₆ D₆, 23° C.): δ 7.10 (s, 2 H, Ar), 2.25 (s,3 H, Ar-CH₃), 1.89 (septet, J_(H-H) =6.6 Hz, 1 H, Me₂ CHCH₂ --), 1.50(s, 18 H, tBu), 0.89 (d, J_(H-H) =6.6 Hz, 6 H, Me₂ CHCH₂ --), 0.50 (d,J_(H-H) =7.2 Hz, 2 H, Me₂ CHCH₂ --). ¹⁹ F NMR (C₆ D₆, 23° C.): δ-120.93(dd, ³ J_(F-F) =18.3 Hz, 2 F, o-F), -149.65 (t, ³ J_(F-F) =21.4 Hz, 1 F,p-F), -159.61 (tt, ³ J_(F-F) =24.5 Hz, 2 F, m-F). iBuAl(C₆ F₅)₂ ¹ H NMR(C₆ D₆, 23° C.): δ 1.89 (overlapping with the above structure, 1 H, Me₂CHCH₂ --), 0.99 (d, J_(H-H) =6.6 Hz, 6 H, Me₂ CHCH₂ --), 0.55 (s, br, 2H, Me₂ CHCH₂ --). ¹⁹ F NMR (C₆ D₆, 23° C.): δ -121.74 (d, ³ J_(F-F)=18.3 Hz, 2 F, o-F), -151.45 (t, ³ J_(F-F) =20.9 Hz, 1 F, p-F), -161.20(tt, ³ J_(F-F) =24.5 Hz, 2 F, m-F). (C₆ F₅)₂ Al(BHT) ¹ H NMR (C₆ D₆, 23°C.): δ 7.13 (s, 2 H, Ar), 2.28 (s, 3 H, Ar-CH₃), 1.53 (s, 18 H, tBu). ¹⁹F NMR (C₆ D₆, 23° C.): δ -120.93(overlapping with other species, 2 F,o-F), -147.41 (t, ³ J_(F-F) =21.14 Hz, 1 F, p-F), -159.12 (tt, ³ J_(F-F)=24.5 Hz, 2 F, m-F).

The metal complex,(t-butylamido)(tetramethylcyclopentadienyl)-dimethylsilanetitaniumdimethyl, (8 μmol) was added to the above solution and the resultingmixture immediately turned to an orange color. NMR spectroscopicfeatures of the major product are consistent with a -bridged bisadductof the formula Me₂ Si(η⁵ -Me₄ C₅)(t-BuN)Ti[(μ-Me)Al(C₆ F₅)₃ ]₂.

Example 5

In a glove box, FAAL (0.032 Amol, toluene adduct) was dissolved in 0.7mL of benzene-d₆ in a J-Young NMR tube and MMAO-3A (4 μmol,FAAL/MMAO=8/1) was added. The NMR spectroscopic features of the productwere consistent with a mixture of the formula: (Ar₃ Al)(AlQ¹ ₃)₀.05[(--AlQ² --O--)₂₋₂₀ ]₀.08, where Ar is pentafluorophenyl and Q¹ and Q²are methyl or isopropyl. The metal complex(t-butylamido)(tetramethylcyclopentadienyl)dimethylsilanetitaniumdimethyl, (8 μmol) was added to the above solution and the resultingmixture immediately turned to orange color. NMR spectroscopic featuresof the major product are consistent with a μ-bridged bisadduct of theformula: Me₂ Si(η⁵ - Me₄ C₅)(t-BuN)Ti[(μ-Me)Al(C₆ F₅)₃ ]₂.

What is claimed is:
 1. An ansa bis(μ-substituted) Group 4 metal andaluminum compound corresponding to the formula: ##STR14## wherein: L' isa π-bonded group,M is a Group 4 metal, J is nitrogen or phosphorus; Z isa divalent bridging group, R' is an inert monovalent ligand; r is one ortwo; X independently each occurrence is a Lewis basic ligand group ableto form a μ-bridging ligand group, and optionally the two X groups maybe joined together, and A' independently each occurrence is analuminum-containing Lewis acid compound of up to 50 atoms other thanhydrogen, that forms an adduct with the metal complex by means of theμ-bridging groups, and optionally two A' groups may be joined togetherthereby forming a single difunctional Lewis acid containing compound. 2.The compound of claim 1 wherein X is selected from the group consistingof hydrocarbyl, silyl, N,N-dialkylamido and alkandiylamido groups of upto 20 atoms not counting hydrogen, or two such X groups together are analkanediyl or alkenediyl group which together with M form ametallocycloalkane or metallocycloalkene.
 3. The compound of claim 1wherein A' is a compound corresponding to the empirical formula:(AlAr^(f) _(3-w') Q¹ _(w'))_(w) (AlAr^(f) _(3-x') (OQ²)_(x'))_(x) (AlQ¹_(3-y') (OQ²)_(y'))_(y) [(--AlQ² --O--)_(z') ]_(z), where;Ar^(f) is afluorinated aromatic hydrocarbyl moiety of from 6 to 30 carbon atoms; Q¹is C₁₋₂₀ alkyl; Q² is C₁₋₂₀ hydrocarbyl, optionally substituted with oneor more groups which independently each occurrence are hydrocarbyloxy,hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbylsilyl)amino,hydrocarbylamino, di(hydrocarbyl)amino, di(hydrocarbyl)phosphino, orhydrocarbylsultido groups having from 1 to 20 atoms other than hydrogen,or, optionally, two or more Q² groups may be covalently linked with eachother to form one or more fused rings or ring systems; w' is a numberfrom 0 to 3; w is a number from 0 to 1.0 x' is a number from 0 to 3; xis a number from 1.0 to 0; y' is a number from 0 to 3; y is a numberfrom 1.0 to 0; z' is a number from 0 to 30; and z is a number from 0 to20.
 4. The compound of claim 3 wherein A' is prepared by exchangebetween tris(pentafluorophenyl)boron and an alkylaluminum- oralkyaluminumoxy-compound.
 5. The compound of claim 1 corresponding tothe formula: ##STR15## wherein: R' is hydrocarbyl or silyl of up to 20atoms not counting hydrogen;R" in each occurrence independently isselected from the group consisting of hydrogen, hydrocarbyl, silyl,N,N-dialkylamino, and alkanediylamino, said R" having up to 20 atoms,not counting hydrogen, or adjacent R" groups are joined together therebyforming a fused ring system, X independently each occurrence ishydrocarbyl, or two X groups together are an alkanediyl or alkenediylgroup, said X having up to 20 atoms not counting hydrogen; Z is SiR*₂,CR*2, SiR*₂ SiR*₂, CR*₂ CR*₂, CR*═CR*, CR*₂ SiR*₂, BNR*₂, or GeR*₂,wherein R* is C₁₋₄ alkyl or C₆₋₁₀ aryl, or optionally two R* groups arejoined together; and A' is as defined in claim
 1. 6. A compoundaccording to claim 5 corresponding to the formula: ##STR16## wherein:Cp* is tetramethylcyclopentadienyl, 2-methyl-4-phenylinden-1-yl,3-pyrrolidinoinden-1-yl, 1-indacenyl, or3,4-(cyclopenta(l)phenanthren-1-yl;R' is C₁₋₁₀ (alkyl or cycloalkyl; Xis methyl; and A' is as defined in claim
 1. 7. A compound according toclaim 5 wherein Cp* is cyclopentadienyl, tetramethylcyclopentadienyl,indenyl, 2,3-dimethylindenyl, fluorenyl, 2-methylindenyl,2-methyl-4-phenylindenyl, 3-dimethylaminoindenyl, 3-pyrrolidinoindenyl,3-piperidinoindenyl, tetrahydrofluorenyl, octahydrofluorenyl,1-indacenyl, 3,4-(cyclopenta(ophenanthren-1-yl), or tetrahydroindenyl.8. A process for preparing a metal complex according to claim 1comprising contacting a charge-neutral Group IV metal coordinationcomplex having at least two Lewis basic groups corresponding to theformula ##STR17## with at least two molar equivalents of charge-neutralaluminum coordination complexes, A', having Lewis acidic aluminum atomssuch that at least two of the aluminum atoms of the aluminumcoordination complexes bond to at least two of the Lewis basic groups ofthe Group IV coordination complex, wherein Z, L', R', r, M, X and A' areas defined in claim
 1. 9. A process for the polymerization of α-olefinscomprising contacting one or more α-olefins with a catalyst compositioncomprising:1) a group 4 metal complex corresponding to the formula:##STR18## wherein, Z, L', M, X, R', and r are as previously defined inclaim 1; and 2) tris(perfluorophenyl)aluminum, wherein the equivalentratio of metal complex: tris(perqluorophenyl) aluminum is from 1:2 to1:5.